This invention relates to urethane polymer compositions, particularly moisture-reactive hot-melt urethane polymer compositions useful as adhesives, to a method for making such compositions, and to a method for bonding substrates with such compositions.
U.S. Pat. No. 6,579,406 discloses moisture-reactive hot-melt adhesives that incorporate styrene/allyl alcohol addition copolymers into a polyurethane prepolymer-forming reaction mixture containing amorphous polyesters or polyethers. These adhesives achieve good “green strength” (i.e., adhesive strength prior to completion of the reaction with moisture), but alternative and/or additional ingredients are desired in order to adjust the formulation to achieve specific balance of properties.
The problem faced by the inventor is the provision of an alternative moisture-reactive hot-melt adhesive composition. Surprisingly, the inventor found that incorporation of anhydride-functional polymers provided the desired balance of properties.